1. Field of the Invention
The present invention relates to a warming device heated by the exothermic reaction of oxidation of iron powders or iron filings, and more particularly, to such a device which uses a combination of a pouch in which iron powders and acid salts of metals are housed, and a water-carrying body containing water.
2. Brief Description of the Prior Art
Recently developed body warmers are so-called chemical body warmers which generate heat by the oxidizing reaction of iron powder, etc., and which do not have rapid combustion, in comparison with the conventional body warmers which have a combustion mechanism as a heat generator. The chemical body warmer has a container containing a mixture of, mainly, malleable iron, carbon powder, metal salts and water, and covering member which covers the mixture so that air is excluded until the device is used. In use, the container is taken out of the covering member, the substances contained in the container are well shaken and thus air is supplied causing the exothermic reaction.
Although these body warmers are sufficiently convenient ones, the duration of heat generation in an appropriate amount, in case such devices are worn on a person's body is short, and is limited to 20-24 hours at the longest. Furthermore, from the point of view of complete utilization of iron at one-time use, there is the disadvantage that in spite of the existence of substantial amounts of unreacted iron after the use of the device, sufficient temperatures for supplying heat to a body warmer can not be maintained. Therefore, it can be said that such conventional devices have still uneconomical defects in view of the resources and energy conservation required at the present time.
The conventional devices have an advantage that there is no necessity of supplying water at the time of using them. However, since water is contained therein initially and strong generation of heat is created only by supplying air, the manufacturing of those devices should be carried out while excluding contact with air, preferably in an atmosphere of nitrogen.
This is, however, a practically impossible manufacturing method, so that it has been necessary to manufacture them in the air. Therefore, oxidation of the iron powders proceeds and generates heat during the manufacturing of those conventional devices and as a result, energy is wasted. Still further, the conventional devices have the disadvantage that during storage thereof, air gradually penetrates into the inside of the device through the outer cover to cause deterioration of the device, and moisture inside of the device gradually evaporates, so that heat cannot be generated when needed.